The High Surf Advisory will remain in effect through 6pm this evening along our north and northwest facing shores due to a large west-northwest to northwest swell. The westerly component of this swell has been severely blocked by our neighbor islands but select breaks should open up today as the swell swings out of a more northwesterly direction. To make things worse, the howling tradewinds will shred the conditions to slop and chop. Be aware that some north shore breaks could rise to double-overhead levels if we’re lucky, but lets not put too much faith in that. A northwest reinforcement is possible tomorrow but it probably won’t add any size, instead prolonging the swell another day or so. Looking to the western North Pacific, a low is developing as expected just east of Japan and it is predicted to set up a fetch aimed fairly well in our direction. The source will remain far from our islands and the long travel distance will greatly decrease the potential of this swell. This energy should reach our shores around Friday, most likely around moderate levels. The bad news is that this will be another west-northwest swell and much of it will be blocked here on Maui. There isn’t much else to discuss at the moment, so pray for surf!
North and northwest facing shores will range from flat to 5-8+ foot today as the swell turns more northwesterly, so be patient. Upper West shores will likely remain blocked with surf only around 0-4 foot. South facing shores may still offer moderate surf around 3-5 foot and some areas may still pick up some action out of the west if you know where to look. Windswell along hte east and northeast facing shores will stay rather small at 2-4 foot but we should see a rise beginning Tuesday, potentially reaching advisory levels by mid-week. Good luck.
Wind and Tide Information
High tide at Kahului was 2.11 foot at 12:09 AM just after midnight, dropping to a low of 1.15 foot at 6:01 AM early this morning, then rising to a high of 1.61 foot at 10:28 AM this morning, before once again dropping to a low of -0.22 foot at 5:24 PM late this afternoon. The sunrise was at 06:51 am this morning and will set at 05:46 pm early this evening. The Moon is in a waning crescent phase and will reach New Moon Wednesday.
Weather Outlook for Sunday
Winds will increase and become more northeasterly across the state through mid-week as high pressure rebuilds to the northeast. Instability in the middle atmosphere overhead will encourage more shower activity as well, mainly over windward slopes, though rainfall will remain mostly light.
The Lihue sounding showed a substantial increase in momentum below the inversion, and wind observations from around the main Hawaiian islands reported that a fair amount reached the surface. Pressure trends, while uneven, suggested further increases in wind speed through the short run.
Although the air mass held water vapor near typical amounts, and windward showers redistributed themselves more evenly overnight, accumulation across the state diminished. The vertical structure of the air mass was closer to climatology, and building orographic forcing should boost precipitation while the moisture remains available, but guidance was nearly unanimous in predicting a drying trend at least through the middle of the coming week. The forecast package continues the plan of increasing pops but low qpf.
Aloft, ridging arched northeast across the state, but troughing edged in from the east to the south of the ridge. Very cold air associated with the trough advanced west far ahead of it. In the presence of a trigger, this cold air aloft could kick off deep convection, but in the presently unsupportive environment, it had little effect at the surface. A deeper mid-level trough to the west made little progress toward the islands.
Guidance still agreed fairly well that the nearby features aloft will shift west through the forecast period. The ridge will remain the most significant overall, supporting the subtropical ridge at the surface to the northeast. Thus, trade winds will continue to rebuild well into the coming week. The trough extending from east to west through the middle of the ridge, right over the state, will destabilize the atmosphere locally. Most solutions downplay the Risk of deep convection, though trade-wind showers may develop more than might be expected otherwise, as much as limited moisture allows.
Outlier solutions predict a Risk of thunderstorms northeast of the islands around Wednesday night. Also, higher elevations could be at Risk for both strong winds and a bit of wintry precipitation, depending on just how sharp the height gradient aloft will be, and whether any moisture makes it up to summit elevations, respectively. For now, none of the these possibilities appear likely to occur. The rest of the forecast looks like a period of returning trades.
Central Valley (Kahului, Spreckelsville):
Sunny with isolated showers. Highs 76 to 82. Northeast winds 10 to 15 mph. Gusts up to 25 mph increasing to 35 mph in the late morning and afternoon. Chance of rain 20 percent.
Leeward West (Lahaina, Ka`anapali):
Mostly sunny with isolated showers. Highs 75 to 83. Northeast winds 10 to 15 mph. Chance of rain 20 percent.
Windward West (Wailuku, Waiehu):
HIGH SURF ADVISORY IN EFFECT UNTIL 6 PM HST THIS EVENING. Partly sunny in the morning then clearing. Scattered showers. Breezy. Highs 63 to 78. East winds 10 to 15 mph increasing to 15 to 25 mph in the late morning and afternoon. Chance of rain 50 percent.
Windard Haleakala (Hana, Haiku, Makawao):
HIGH SURF ADVISORY IN EFFECT UNTIL 6 PM HST THIS EVENING. Partly sunny with scattered showers. Breezy. Highs around 75 at the shore to around 62 at 5000 feet. East winds 10 to 15 mph increasing to 10 to 25 mph in the late morning and afternoon. Chance of rain 50 percent.
Leeward Haleakala (Kihei, Wailea, Makena):
Sunny. Isolated showers in the afternoon. Highs around 80 at the shore to around 65 at 5000 feet. East winds around 10 mph with higher gusts shifting to the southwest with gusts to 40 mph in the late morning and afternoon. Chance of rain 20 percent.
Sunny with isolated showers. Windy. Highs around 66 at 7000 feet to around 61 at the summit. East winds 15 to 30 mph. Chance of rain 20 percent.